\section{Scenario for entering a query compound}
\begin{description}
  \item [INITIAL ASSUMPTION:]
    \textnormal{The user opens the PPS prediction page. He enters a compound by drawing it, or by directly entering a SMILES string. The user clicks on the continue button. }
 \item [NORMAL:]
    \textnormal{The user will be taken to a status page that displays the query compound, the query submission time and the prediction run-time. When the prediction is finished, the user will be directed to the pathway prediction results page.}
 \item [WHAT CAN GO WRONG:]
    \textnormal{The compound entered by the user does not exist. The user will be forwarded to an error page that contains a clear error message. As a solution to the problem the user will be advised to enter a query compound again, to visit the help page or to start the demo.}
\item [SYSTEM STATE ON COMPLETION]
\textnormal{Prediction is finished. }
\end{description}

\section{Aerobic likelihood filter}
\begin{description}
  \item [INITIAL ASSUMPTION:]
    \textnormal{The user opens the \gls{PPS} prediction page. He enters a compound by drawing it, or by directly entering a \gls{SMILES} string. The user chooses to only see the likely \gls{aerobic transformation}s by clicking on the option aerobic. The user clicks on the continue button.}
 \item [NORMAL:]
    \textnormal{The user will be taken to a status page that displays the query \gls{compound}, the query submission time and the prediction run-time. When the prediction is finished, the user will be forwarded to the pathway prediction results page. Only very likely, likely and neutral biotransformations will be displayed in the predicted pathway.}
 \item [WHAT CAN GO WRONG:]
    \textnormal{No very likely, likely or neutral transformations are found. In this case the system will display a message at the top of the predicted pathway page to notify the user that no aerobic likely transformations were found. The plausible pathway will be displayed including all the predicted transformations.  }
\item [SYSTEM STATE ON COMPLETION]
\textnormal{User is not logged on. }
\end{description}

\section{Expert-user Authentication failure}
\begin{description}
  \item [INITIAL ASSUMPTION:]
    \textnormal{The expert opens the home page. He enters his username and password then clicks on the ok button (session\_start).}
		 \item [NORMAL:]
    \textnormal{The system recognizes the username and the password. The user will be retourned to the same page. The session beginns.}
 \item [WHAT CAN GO WRONG:]
   The system does not recognize the combination of username and password. A clear error message will be displayed. The expert will be advised to re-enter username and password or to request a password reset by the application's administrator. If a user account recieves three false consecutive logins the account will be deactivated. 		
\item [SYSTEM STATE ON COMPLETION]
\textnormal{ User logged on.}
\end{description}